CMake: Fix leak and crash

The crash could be reproduced by opening a project, clicking the "Kit
Configuration" button in the build configuration, closing that dialog,
opening it again, opening the settings from the "Manage" button for the
CMake tools, and closing the settings dialog.

The "KitAspectWidget"s are not really widgets, and by default do not get
a parent, or are otherwise lifetime managed. When "they" are added to a
layout, actually only their widget members are added to the GUI. When
opening and closing the "Kit Configuration" dialog, the widgets were
deleted, but the KitAspectWidget instances were leaked and lived on, the
CMakeKitAspectWidget referencing a now deleted QComboBox, and still
being connected to the CMakeToolManager's signals, which subsequented
crashed when these were sent.

Fixes: QTCREATORBUG-28740
Change-Id: I36db3b6596ef21cc01dc877bca92b9961c0606b9
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

1 files changed, 9 insertions, 6 deletions

diff --git a/src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp b/src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp
index 746a64050e..127e572110 100644
--- a/src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp
@@ -665,12 +665,15 @@ void CMakeBuildSettingsWidget::kitCMakeConfiguration()
 
     auto layout = new QGridLayout(dialog);
 
-    kitAspect.createConfigWidget(m_buildSystem->kit())
-        ->addToLayoutWithLabel(layout->parentWidget());
-    generatorAspect.createConfigWidget(m_buildSystem->kit())
-        ->addToLayoutWithLabel(layout->parentWidget());
-    configurationKitAspect.createConfigWidget(m_buildSystem->kit())
-        ->addToLayoutWithLabel(layout->parentWidget());
+    KitAspectWidget *widget = kitAspect.createConfigWidget(m_buildSystem->kit());
+    widget->setParent(dialog);
+    widget->addToLayoutWithLabel(layout->parentWidget());
+    widget = generatorAspect.createConfigWidget(m_buildSystem->kit());
+    widget->setParent(dialog);
+    widget->addToLayoutWithLabel(layout->parentWidget());
+    widget = configurationKitAspect.createConfigWidget(m_buildSystem->kit());
+    widget->setParent(dialog);
+    widget->addToLayoutWithLabel(layout->parentWidget());
 
     layout->setColumnStretch(1, 1);